A novel de novo 20q13.32-q13.33 deletion in a 2-year-old child with poor growth, feeding difficulties and low bone mass.

Interstitial deletions of the long arm of chromosome 20 are rarely reported in the literature. We report a 2-year-old child with a 2.6 Mb deletion of 20q13.32-q13.33, detected by microarray-based comparative genomic hybridization, who presented with poor growth, feeding difficulties, abnormal subcutaneous fat distribution with the lack of adipose tissue on clinical examination, facial dysmorphism and low bone mass. This report adds to rare publications describing constitutional aberrations of chromosome 20q, and adds further evidence to the fact that deletion of the GNAS complex may not always be associated with an Albright's hereditary osteodystrophy phenotype as described previously.

Genomics for paediatricians: promises and pitfalls.

In recent years, there have been significant advances in genetic technologies, evolving the field of genomics from genetics. This has huge diagnostic potential, as genomic testing increasingly becomes part of mainstream medicine. However, there are numerous potential pitfalls in the interpretation of genomic data. It is therefore essential that we educate clinicians more widely about the appropriate interpretation and utilisation of genomic testing.

Aetiological investigations in early developmental impairment: are they worth it?

OBJECTIVE: To study the frequency a diagnosis is made in children with early developmental impairment (EDI), and the contribution made to diagnosis by specific investigations. DESIGN: Retrospective case note review. SETTING: Community, neurodisability and neurology department at a UK tertiary centre. PARTICIPANTS: Children referred to determine the aetiology of EDI where a cause was not evident on history and examination. Participants were divided into two groups: EDI and no additional features (EDI-) and EDI with additional features (EDI+). MAIN OUTCOME MEASURES: The frequency a cause was found for the child's EDI and which tests contributed to a diagnosis. RESULTS: 699 participants, 68.8% boys, median age at investigation 2 years 8 months (range 3 months to 11 years 5 months). 61 (8.7%) of participants had no investigations, and children with EDI- were less likely to be investigated (χ2=12.5, p<0.05). A diagnosis was made in 166 children (23.7%) and was more frequent in EDI+ (EDI- 9.9%, EDI+ 27.3%, χ2=19.0; p<0.05). Full blood count, zinc protoporphyrin, renal or liver function, bone profile, biotinidase, creatine kinase or lead level revealed no diagnoses. The following investigations found causes for EDI: MRI (23.1%), microarray (11.5%), Fragile X (0.9%), plasma amino acids (1.2%), urine organic acids (0.9%) and thyroid function tests (0.5%). CONCLUSIONS: The majority of 'screening' investigations for EDI do not contribute to a diagnosis, highlighting an area of cost saving for the NHS and reduced burden for patients and families. We propose a streamlined guideline for the investigation of EDI based on our data.